Matilde Achaval - Academia.edu (original) (raw)

Papers by Matilde Achaval

Research paper thumbnail of Lesion of the subthalamic nucleus reverses motor deficits but not death of nigrostriatal dopaminergic neurons in a rat 6-hydroxydopamine-lesion model of Parkinson's disease

Brazilian Journal of Medical and Biological Research, 2010

Research paper thumbnail of The effects of treadmill training on young and mature rats after traumatic peripheral nerve lesion

Neuroscience Letters, 2011

The purpose of this study was to investigate the possible effects of a treadmill training program... more The purpose of this study was to investigate the possible effects of a treadmill training program on regeneration in young (3-month-old) and mature (13-month-old) rats with sciatic nerve crush using functional, electrophysiological, and morphometric analyses. When compared to both the young and mature untrained injury groups, those groups that underwent a treadmill training showed improved sensorimotor function evaluated by narrow

Research paper thumbnail of Repeatability of Infrared Plantar Thermography in Diabetes Patients: A Pilot Study

Journal of Diabetes Science and Technology, 2013

Research paper thumbnail of Plantar Pressure Distribution Patterns of Individuals with Prediabetes in Comparison with Healthy Individuals and Individuals with Diabetes

Journal of Diabetes Science and Technology, 2013

Research paper thumbnail of The Amazonian herbal Marapuama attenuates cognitive impairment and neuroglial degeneration in a mouse Alzheimer model

Phytomedicine, 2011

Alzheimer's disease (AD) is expected to affect more than 22 million people worldwide by 2025, cau... more Alzheimer's disease (AD) is expected to affect more than 22 million people worldwide by 2025, causing devastating suffering and enormous costs to families and society. AD is a multifactorial disease, with a complex pathological mosaic. In rodents, AD-like dementia can be induced by cerebral microinjection of A␤ peptide, leading to amyloid deposits, amnesia and various features of neurodegeneration. Marapuama (Ptychopetalum olacoides) is regarded as a "brain tonic" in the Amazon region and shows a nootropic profile in rodents. Aim of the study: Because a specific extract (POEE) of Marapuama was shown to possess promnesic and anti-amnesic properties, the aim of this study was to verify if POEE is also effective against A␤ 1-42 -induced cognitive deficit in mice. Additionally, A␤ deposits (Congo red), GFAP immunoreactivity (immunohistochemistry), and neurodegenerative changes in the hippocampal pyramidal layer (Nissl) were examined as measures of A␤ 1-42 -induced neurodegeneration. Materials and methods: CF1 mice were subjected to the experimental Alzheimer model with the A␤ 1-42 i.c.v. administration. The effects of POEE 800 mg/kg were evaluated over 14 consecutive days of treatment. Results: The data show that 14 days of oral treatment with POEE (800 mg/kg) was effective in preventing A␤-induced cognitive impairment, without altering the levels of BDNF and with parallel reductions in A␤ deposits and astrogliosis. CA1 hippocampus loss induced by A␤ 1-42 was also diminished in POEE-treated mice.

Research paper thumbnail of Physical exercise down-regulated locomotor side effects induced by haloperidol treatment in Wistar rats

Pharmacology Biochemistry and Behavior, 2013

Extra-pyramidal symptoms (EPS) such as akinesia, dystonia, gait alteration and tremors are observ... more Extra-pyramidal symptoms (EPS) such as akinesia, dystonia, gait alteration and tremors are observed when dopamine D2-receptors are blocked by pharmacological agents such as haloperidol. These alterations produce a Parkinson disease-like state (PLS). Physical exercise has been proven to improve gait and locomotor symptoms in Parkinson's disease; we sought to elucidate the effects of physical exercise on PLS induced by chronic administration of haloperidol in rats. We used 48 rats distributed into four groups: Control, Exercise, Haloperidol, and Hal+Exe. All the animals received a daily injection of saline or haloperidol for 30 days, and the exercise groups underwent a daily 30-minute exercise protocol for 20 days. The animals were subjected to the ink-paw test, bar test and open-field test throughout the training period. The haloperidol-induced akinesia increased throughout the days of injections, but exercise was shown to alleviate it. The assessment showed shortened stride length and increased stance width with the use of haloperidol, which were significantly alleviated by exercise. These results indicate that exercise could be an interesting approach towards reducing unwanted EPS caused by haloperidol.

Research paper thumbnail of Capsaicin-induced avoidance behavior in the terrestrial Gastropoda Megalobulimus abbreviatus: Evidence for TRPV-1 signaling and opioid modulation in response to chemical noxious stimuli

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2007

The aim of this study was to measure the nociceptive response (avoidance latency) of the land sna... more The aim of this study was to measure the nociceptive response (avoidance latency) of the land snail Megalobulimus abbreviatus (N = 8 in each group) after topical capsaicin exposure (0.1% and 0.5% in 20% ethanol) and to compare it to a well-studied stressful (50°C) thermal stimulus model. We also tested if ruthenium red, and capsazepine, respectively nonselective and selective TRPV1 receptor antagonists, could modify both capsaicin-and thermal-evoked responses. Finally, animals were pretreated with morphine, naloxone or morphine plus naloxone prior to capsaicin stimuli. Latencies were measured when the animal lifted its head-foot complex 1 cm from the substrate. Data were compared using ANOVA and LSD post hoc, and the Student T Test (p b 0.05). Capsaicin elicited dose-dependent withdrawal behavior. The capsaicin vehicle (20% ethanol) also evoked a less intense but significant avoidance reaction. Capsazepine and ruthenium red attenuated both capsaicin and heat withdrawal responses, when compared to vehicles. Morphine increased, and naloxone, either alone or in combination with morphine, reduced capsaicin-evoked latencies when compared to morphine or saline. These results indicate that the TRPV1 receptor plays a role in the nociceptive circuits of M. abbreviatus.

Research paper thumbnail of Vascular supply of the central nervous system of the land snail Megalobulimus oblongus (Gastropoda, Pulmonata)

Brazilian Journal of Medical and Biological Research, 2003

The vascularization of the central nervous system of the snail Megalobulimus oblongus was studied... more The vascularization of the central nervous system of the snail Megalobulimus oblongus was studied by injection of carmine-gelatin solution into the arterial system and using a histochemical technique for the detection of alkaline phosphatase. The central nervous system of M. oblongus is irrigated by the anterior aorta, from which a series of small branches emerge that supply the subesophageal nervous ganglia. In turn, these branches give rise to a series of smaller vessels that irrigate the buccal bulb, the anterior portion of the foot, the cerebral ganglia, the dorsal body gland, and the anterior portion of the reproductive system. No hemolymph vessels were detected within nervous tissue although such vessels were found in the periganglionic connective sheath. This connective sheath contains vascular loops and had a series of overlaps and projections that follow the contour of the nervous ganglia. This arrangement permits a larger area of interaction between the surface of the nervous tissue and the hemolymph and reduces the distance between the deepest portion of a given ganglion and the hemolymph vessels.

Research paper thumbnail of A simple and fast densitometric method for the analysis of tyrosine hydroxylase immunoreactivity in the substantia nigra pars compacta and in the ventral tegmental area

Brain Research Protocols, 2005

Parkinson's disease is a progressive dyskinetic disorder caused by degeneration of mesencephalic ... more Parkinson's disease is a progressive dyskinetic disorder caused by degeneration of mesencephalic dopaminergic neurons in the substantia nigra pars compacta (SNpc) and, to a lesser extent, in the ventral tegmental area (VTA). Tyrosine hydroxylase (TH) is a rate-limiting enzyme for dopamine synthesis, therefore immunohistochemistry for TH can be used as an important marker of dopaminergic cell loss in these regions. Traditionally, immunohistochemical experiments are analyzed qualitatively by optical microscopic observation or more rarely semiquantitatively evaluated by densitometry. A common problem with such papers is the lack of a clear explanation of the algorithms and macros employed in the semi-quantitative approaches. In this paper, we describe, in detail, an easy, fast and precise protocol for the analysis of TH immunoreactivity in SNpc and VTA using one of the most popular image analysis software packages (Image Pro-Plus). We believe that this protocol will facilitate the evaluation of mesencephalic TH immunoreactivity in various available animal models of Parkinson's disease. D

Research paper thumbnail of Plastic changes induced by neonatal handling in the hypothalamus of female rats

Brain Research, 2007

Early-life events can exert profound long-lasting effects on several behaviors such as fear/ anxi... more Early-life events can exert profound long-lasting effects on several behaviors such as fear/ anxiety, sexual activity, stress responses and reproductive functions. Present study aimed to examine the effects of neonatal handling on the volume and number of cells in the hypothalamic paraventricular nucleus (pPVN, parvocellular and mPVN, magnocellular regions) and the supraoptic nucleus (SON) in female rats at 11 and 90 days of age. Moreover, in the same areas, immunohistochemistry for oxytocin (OT) and glial fibrillary acidic protein (GFAP) were analyzed in the adult animals. Daily handling during the first 10 postnatal days reduced the number of cells in the pPVN and SON at both the 11 and 90 days. Handling decreased the number of OTpositive parvocellular cells in the PVN in adult females. No significant differences were detected on the optical density (OD) of GFAP-positive cells between the handled and nonhandled adult females. The effect of handling on cell loss was observed 24 h after the 10-day handling period and persisted into adulthood, indicating a stable morphological trace. Results suggest that neonatal handling can induce plastic changes in the central nervous system. Oxytocin Plasticity Development Paraventricular nucleus Supraoptic nucleus B R A I N R E S E A R C H 1 1 7 0 ( 2 0 0 7 ) 2 0 -3 0 ava i l a b l e a t w w w. s c i e n c e d i r e c t . c o m w w w. e l s ev i e r. c o m / l o c a t e / b r a i n r e s

Research paper thumbnail of Failure of estrogen to protect the substantia nigra pars compacta of female rats from lesion induced by 6-hydroxydopamine

Research paper thumbnail of Temporal profiles of the in vitro phosphorylation rate and immunocontent of glial fibrillary acidic protein (GFAP) after kainic acid-induced lesions in area CA1 of the rat hippocampus: demonstration of a novel phosphoprotein associated with gliosis

Brain Research, 1997

The in vitro phosphorylation rate and immunocontent of glial fibrillary acidic protein was studie... more The in vitro phosphorylation rate and immunocontent of glial fibrillary acidic protein was studied in slices of area CA1 of the rat hippocampus after stereotaxic injection of 1 nmol of kainic acid. For controls the contralateral hippocampus was injected with saline.

Research paper thumbnail of Gonadal hormone regulation of glial fibrillary acidic protein immunoreactivity in the medial amygdala subnuclei across the estrous cycle and in castrated and treated female rats

Brain Research, 2006

The medial amygdala (MeA) is a sexually dimorphic area that modulates neuroendocrine and behavior... more The medial amygdala (MeA) is a sexually dimorphic area that modulates neuroendocrine and behavioral activities and where gonadal hormones play an important role in neuronglial and synaptic plasticity. Immunohistochemistry was used to identify the astrocytic marker glial fibrillary acidic protein (GFAP) in the different MeA subnucleianterodorsal (MeAD), posterodorsal (MePD) and posteroventral (MePV)of intact female rats in the different phases of the estrous cycle and in ovariectomized females treated with hormonal substitutive therapy. Data semi-quantified by optical densitometry showed that, in the proestrus phase, the GFAP immunoreactivity (GFAP-ir) was higher when compared to the other phases of the estrous cycle (P < 0.02). GFAP-ir was also higher in the MePD than in the MeAD or in the MePV (P < 0. 02). In ovariectomized females, injections of estradiol alone or estradiol plus progesterone increased GFAP-ir in the MePD and in the MePV (P < 0.001), but not in the MeAD (P > 0.3), when compared to control data. These findings suggest that astrocytic GFAP in the MeA subnuclei can be affected either by physiological levels or by hormonal manipulation of the ovarian steroids, which may contribute to the plasticity of local and integrated functional activities of these brain areas in female rats.

Research paper thumbnail of Glial alterations in the hippocampus of rats submitted to ibotenic-induced lesion of the nucleus basalis magnocellularis

Behavioural Brain Research, 2008

Lesion of the nucleus basalis magnocellularis (nbm) is a suitable approach to study cognitive def... more Lesion of the nucleus basalis magnocellularis (nbm) is a suitable approach to study cognitive deficit and behavior alterations involving cholinergic dysfunction, which is associated with the major types of dementia. Cortical astrogliosis also has been described in this model, but it is not clear whether hippocampal astrocytes are activated. In this study, we investigated possible specific astrocyte alterations in the hippocampi of Wistar rats submitted to nbm damage with ibotenic acid, investigating the content and immunohistochemistry of glial fibrillary acidic protein (GFAP), as well as S100B protein content, glutamate uptake and glutamine synthetase activity on the 7th and 28th post-lesion days. Cognitive deficit was confirmed by the step-down inhibitory avoidance task. Interestingly, we found a decrease in GFAP content, S100B content and glutamate uptake activity in the hippocampus on the 28th day after nbm lesion. No alterations were observed in glutamine synthetase activity or in the cerebrospinal fluid S100B content. Although our data suggest caution in the use of nbm lesion with ibotenic acid as a dementia model, it is possible that these alterations could contribute to the cognitive deficit observed in these rats.

Research paper thumbnail of Prenatal Stress Produces Social Behavior Deficits and Alters the Number of Oxytocin and Vasopressin Neurons in Adult Rats

Neurochemical Research

The present study investigated the long-lasting effects of prenatal repeated restraint stress on ... more The present study investigated the long-lasting effects of prenatal repeated restraint stress on social behavior and anxiety, as well as its repercussions on oxytocin (OT) and vasopressin (VP)-positive neurons of the paraventricular (PVN) and supraoptic (SON) nuclei from stressed pups in adulthood. Female Wistar rats were exposed to restraint stress in the last 7 days of pregnancy. At birth, pups were cross-fostered and assigned to the following groups: prenatally non-stressed offspring raised by prenatally non-stressed mothers (NS:NS), prenatally non-stressed offspring raised by prenatally stressed mothers (S:NS), prenatally stressed offspring raised by prenatally non-stressed mothers (NS:S), prenatally stressed offspring raised by prenatally stressed mothers (S:S). As adults, male prenatally stressed offspring raised both by stressed mothers (S:S group) and non-stressed ones (NS:S group) showed impaired social memory and interaction. In addition, when both adverse conditions coexi...

Research paper thumbnail of Hippocampal alterations in rats submitted to streptozotocin-induced dementia model are prevented by aminoguanidine

Journal of Alzheimer's disease : JAD, 2009

Although the exact cause of Alzheimer's disease remains elusive, many possible risk factors a... more Although the exact cause of Alzheimer's disease remains elusive, many possible risk factors and pathological alterations have been used in the elaboration of in vitro and in vivo models of this disease in rodents, including intracerebral infusion of streptozotocin (STZ). Using this model, we evaluated spatial cognitive deficit and neurochemical hippocampal alterations, particularly astroglial protein markers such as glial fibrillary acidic protein (GFAP) and S100B, glutathione content, nitric oxide production, and cerebrospinal fluid (CSF) S100B. In addition, prevention of these alterations by aminoguanidine administration was evaluated. Results confirm a spatial cognitive deficit and nitrative stress in this dementia model as well as specific astroglial alterations, particularly S100B accumulation in the hippocampus and decreased CSF S100B. The hippocampal astroglial activation occurred independently of the significant alteration in GFAP content. Moreover, all these alterations...

Research paper thumbnail of Ultrastructural analysis of the dorsal body gland of the terrestrial snail Megalobulimus abbreviatus (Becquaert, 1948)

Brazilian journal of biology = Revista brasleira de biologia

The ultrastructure of the reproductive gland, dorsal body (DB), of Megalobulimus abbreviatus was ... more The ultrastructure of the reproductive gland, dorsal body (DB), of Megalobulimus abbreviatus was analysed. Electron microscope immunohistochemistry was used to detect FMRFamide-like peptides in the nerve endings within this gland. Nerve backfilling was used in an attempt to identify the neurons involved in this innervation. In M. abbreviatus, the DB has a uniform appearance throughout their supraesophageal and subesophageal portions. Dorsal body cells have several features in common with steroid-secreting gland cells, such as the presence of many lipid droplets, numerous mitochondria with tubular cristae and a developed smooth endoplasmic reticulum cisternae. Throughout the DB in M. abbreviatus numerous axonal endings were seen to be in contact with the DB cells exhibiting a synaptic-like structure. The axon terminals contained numerous electron-dense and scanty electron-lucid vesicles. In addition, the DB nerve endings exhibited FMRFamide immunoreactive vesicles. Injection of neura...

Research paper thumbnail of Acetylcholinesterase distribution in the central nervous system of the Megalobulimus oblongus (Gastropoda, Pulmonata)

Archives d'anatomie, d'histologie et d'embryologie normales et expérimentales

The acetylcholinesterase (AChE) in the central nervous system (CNS) of the Megalobulimus oblongus... more The acetylcholinesterase (AChE) in the central nervous system (CNS) of the Megalobulimus oblongus was demonstrated by using Koelle and Friedenwald's procedure. The AChE positive reaction was revealed in the nervous cell bodies and processes in the different ganglia of the CNS. The largest number of strong positive neuronal subsets reside in pedal and buccal ganglia. Other positive cell bodies are also located in clusters in the left portion of the visceral ganglion, meso and postcerebrum, and pleural ganglia. In some neurons the enzymatic reaction only appeared at trophospongium level. The neuropilian synaptic areas also exhibited AChE reactivity. These data provide further evidence that AChE is present in neuronal bodies of the CNS of this pulmonate snail, and in some areas is probably involved in cholinergic circuits.

Research paper thumbnail of Distribution of NADPH-diaphorase activity in the central nervous system of the young and adult land snail Megalobulimus abbreviatus

Tissue and Cell

Nitric oxide (NO) is a gas produced through the action of nitric oxide synthase that acts as a ne... more Nitric oxide (NO) is a gas produced through the action of nitric oxide synthase that acts as a neurotransmitter in the central nervous system (CNS) of adult gastropod mollusks. There are no known reports of the presence of NOS-containing neurons and glial cells in young and adult Megalobulimus abbreviatus. Therefore, NADPH-d histochemistry was employed to map the nitrergic distribution in the CNS of young and adult snails in an attempt to identify any transient enzymatic activity in the developing CNS. Reaction was observed in neurons and fibers in all CNS ganglia of both age groups, but in the pedal and cerebral ganglia, positive neurons were more intense than in other ganglia, forming clusters symmetrically located in both paired ganglia. However, neuronal NADPH-d activity in the mesocerebrum and pleural ganglia decreased from young to adult animals. In both age groups, positive glial cells were located beneath the ganglionic capsule, forming a network and surrounding the neuronal...

Research paper thumbnail of Carbohydrate metabolism in the central nervous system of the Megalobulimus oblongus snail during anoxia exposure and post-anoxia recovery

Journal of Experimental Zoology Part A Comparative Experimental Biology

The effects of anoxic exposure and the post-anoxia aerobic recovery period on carbohydrate metabo... more The effects of anoxic exposure and the post-anoxia aerobic recovery period on carbohydrate metabolism in the central nervous system (CNS) of the land snail Megalobulimus oblongus, an anoxia-tolerant land gastropod, were studied. The snails were exposed to anoxia for periods of 1.5, 3, 6, 12, 18, or 24 hr. In order to study the post-anoxia recovery phase, snails exposed to a 3-hr period of anoxia were returned to aerobic conditions for 1.5, 3, 6, or 15 hr. Glycogen and glucose concentrations in the CNS, hemolymph glucose concentration, and glycogen phosphorylase (active form, GPa) activity in the CNS were analyzed. Anoxia does not significantly affect the concentration of CNS glucose but induces hyperglycemia and a reduction of CNS GPa activity. The glycogen concentration was decreased at 12 hr of anoxia; however, by 18 and 24 hr in anoxia, the glycogen content was not significantly different from basal control values. During the post-anoxia period, the reduction in GPa activity and ...

Research paper thumbnail of Lesion of the subthalamic nucleus reverses motor deficits but not death of nigrostriatal dopaminergic neurons in a rat 6-hydroxydopamine-lesion model of Parkinson's disease

Brazilian Journal of Medical and Biological Research, 2010

Research paper thumbnail of The effects of treadmill training on young and mature rats after traumatic peripheral nerve lesion

Neuroscience Letters, 2011

The purpose of this study was to investigate the possible effects of a treadmill training program... more The purpose of this study was to investigate the possible effects of a treadmill training program on regeneration in young (3-month-old) and mature (13-month-old) rats with sciatic nerve crush using functional, electrophysiological, and morphometric analyses. When compared to both the young and mature untrained injury groups, those groups that underwent a treadmill training showed improved sensorimotor function evaluated by narrow

Research paper thumbnail of Repeatability of Infrared Plantar Thermography in Diabetes Patients: A Pilot Study

Journal of Diabetes Science and Technology, 2013

Research paper thumbnail of Plantar Pressure Distribution Patterns of Individuals with Prediabetes in Comparison with Healthy Individuals and Individuals with Diabetes

Journal of Diabetes Science and Technology, 2013

Research paper thumbnail of The Amazonian herbal Marapuama attenuates cognitive impairment and neuroglial degeneration in a mouse Alzheimer model

Phytomedicine, 2011

Alzheimer's disease (AD) is expected to affect more than 22 million people worldwide by 2025, cau... more Alzheimer's disease (AD) is expected to affect more than 22 million people worldwide by 2025, causing devastating suffering and enormous costs to families and society. AD is a multifactorial disease, with a complex pathological mosaic. In rodents, AD-like dementia can be induced by cerebral microinjection of A␤ peptide, leading to amyloid deposits, amnesia and various features of neurodegeneration. Marapuama (Ptychopetalum olacoides) is regarded as a "brain tonic" in the Amazon region and shows a nootropic profile in rodents. Aim of the study: Because a specific extract (POEE) of Marapuama was shown to possess promnesic and anti-amnesic properties, the aim of this study was to verify if POEE is also effective against A␤ 1-42 -induced cognitive deficit in mice. Additionally, A␤ deposits (Congo red), GFAP immunoreactivity (immunohistochemistry), and neurodegenerative changes in the hippocampal pyramidal layer (Nissl) were examined as measures of A␤ 1-42 -induced neurodegeneration. Materials and methods: CF1 mice were subjected to the experimental Alzheimer model with the A␤ 1-42 i.c.v. administration. The effects of POEE 800 mg/kg were evaluated over 14 consecutive days of treatment. Results: The data show that 14 days of oral treatment with POEE (800 mg/kg) was effective in preventing A␤-induced cognitive impairment, without altering the levels of BDNF and with parallel reductions in A␤ deposits and astrogliosis. CA1 hippocampus loss induced by A␤ 1-42 was also diminished in POEE-treated mice.

Research paper thumbnail of Physical exercise down-regulated locomotor side effects induced by haloperidol treatment in Wistar rats

Pharmacology Biochemistry and Behavior, 2013

Extra-pyramidal symptoms (EPS) such as akinesia, dystonia, gait alteration and tremors are observ... more Extra-pyramidal symptoms (EPS) such as akinesia, dystonia, gait alteration and tremors are observed when dopamine D2-receptors are blocked by pharmacological agents such as haloperidol. These alterations produce a Parkinson disease-like state (PLS). Physical exercise has been proven to improve gait and locomotor symptoms in Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease; we sought to elucidate the effects of physical exercise on PLS induced by chronic administration of haloperidol in rats. We used 48 rats distributed into four groups: Control, Exercise, Haloperidol, and Hal+Exe. All the animals received a daily injection of saline or haloperidol for 30 days, and the exercise groups underwent a daily 30-minute exercise protocol for 20 days. The animals were subjected to the ink-paw test, bar test and open-field test throughout the training period. The haloperidol-induced akinesia increased throughout the days of injections, but exercise was shown to alleviate it. The assessment showed shortened stride length and increased stance width with the use of haloperidol, which were significantly alleviated by exercise. These results indicate that exercise could be an interesting approach towards reducing unwanted EPS caused by haloperidol.

Research paper thumbnail of Capsaicin-induced avoidance behavior in the terrestrial Gastropoda Megalobulimus abbreviatus: Evidence for TRPV-1 signaling and opioid modulation in response to chemical noxious stimuli

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2007

The aim of this study was to measure the nociceptive response (avoidance latency) of the land sna... more The aim of this study was to measure the nociceptive response (avoidance latency) of the land snail Megalobulimus abbreviatus (N = 8 in each group) after topical capsaicin exposure (0.1% and 0.5% in 20% ethanol) and to compare it to a well-studied stressful (50°C) thermal stimulus model. We also tested if ruthenium red, and capsazepine, respectively nonselective and selective TRPV1 receptor antagonists, could modify both capsaicin-and thermal-evoked responses. Finally, animals were pretreated with morphine, naloxone or morphine plus naloxone prior to capsaicin stimuli. Latencies were measured when the animal lifted its head-foot complex 1 cm from the substrate. Data were compared using ANOVA and LSD post hoc, and the Student T Test (p b 0.05). Capsaicin elicited dose-dependent withdrawal behavior. The capsaicin vehicle (20% ethanol) also evoked a less intense but significant avoidance reaction. Capsazepine and ruthenium red attenuated both capsaicin and heat withdrawal responses, when compared to vehicles. Morphine increased, and naloxone, either alone or in combination with morphine, reduced capsaicin-evoked latencies when compared to morphine or saline. These results indicate that the TRPV1 receptor plays a role in the nociceptive circuits of M. abbreviatus.

Research paper thumbnail of Vascular supply of the central nervous system of the land snail Megalobulimus oblongus (Gastropoda, Pulmonata)

Brazilian Journal of Medical and Biological Research, 2003

The vascularization of the central nervous system of the snail Megalobulimus oblongus was studied... more The vascularization of the central nervous system of the snail Megalobulimus oblongus was studied by injection of carmine-gelatin solution into the arterial system and using a histochemical technique for the detection of alkaline phosphatase. The central nervous system of M. oblongus is irrigated by the anterior aorta, from which a series of small branches emerge that supply the subesophageal nervous ganglia. In turn, these branches give rise to a series of smaller vessels that irrigate the buccal bulb, the anterior portion of the foot, the cerebral ganglia, the dorsal body gland, and the anterior portion of the reproductive system. No hemolymph vessels were detected within nervous tissue although such vessels were found in the periganglionic connective sheath. This connective sheath contains vascular loops and had a series of overlaps and projections that follow the contour of the nervous ganglia. This arrangement permits a larger area of interaction between the surface of the nervous tissue and the hemolymph and reduces the distance between the deepest portion of a given ganglion and the hemolymph vessels.

Research paper thumbnail of A simple and fast densitometric method for the analysis of tyrosine hydroxylase immunoreactivity in the substantia nigra pars compacta and in the ventral tegmental area

Brain Research Protocols, 2005

Parkinson's disease is a progressive dyskinetic disorder caused by degeneration of mesencephalic ... more Parkinson's disease is a progressive dyskinetic disorder caused by degeneration of mesencephalic dopaminergic neurons in the substantia nigra pars compacta (SNpc) and, to a lesser extent, in the ventral tegmental area (VTA). Tyrosine hydroxylase (TH) is a rate-limiting enzyme for dopamine synthesis, therefore immunohistochemistry for TH can be used as an important marker of dopaminergic cell loss in these regions. Traditionally, immunohistochemical experiments are analyzed qualitatively by optical microscopic observation or more rarely semiquantitatively evaluated by densitometry. A common problem with such papers is the lack of a clear explanation of the algorithms and macros employed in the semi-quantitative approaches. In this paper, we describe, in detail, an easy, fast and precise protocol for the analysis of TH immunoreactivity in SNpc and VTA using one of the most popular image analysis software packages (Image Pro-Plus). We believe that this protocol will facilitate the evaluation of mesencephalic TH immunoreactivity in various available animal models of Parkinson's disease. D

Research paper thumbnail of Plastic changes induced by neonatal handling in the hypothalamus of female rats

Brain Research, 2007

Early-life events can exert profound long-lasting effects on several behaviors such as fear/ anxi... more Early-life events can exert profound long-lasting effects on several behaviors such as fear/ anxiety, sexual activity, stress responses and reproductive functions. Present study aimed to examine the effects of neonatal handling on the volume and number of cells in the hypothalamic paraventricular nucleus (pPVN, parvocellular and mPVN, magnocellular regions) and the supraoptic nucleus (SON) in female rats at 11 and 90 days of age. Moreover, in the same areas, immunohistochemistry for oxytocin (OT) and glial fibrillary acidic protein (GFAP) were analyzed in the adult animals. Daily handling during the first 10 postnatal days reduced the number of cells in the pPVN and SON at both the 11 and 90 days. Handling decreased the number of OTpositive parvocellular cells in the PVN in adult females. No significant differences were detected on the optical density (OD) of GFAP-positive cells between the handled and nonhandled adult females. The effect of handling on cell loss was observed 24 h after the 10-day handling period and persisted into adulthood, indicating a stable morphological trace. Results suggest that neonatal handling can induce plastic changes in the central nervous system. Oxytocin Plasticity Development Paraventricular nucleus Supraoptic nucleus B R A I N R E S E A R C H 1 1 7 0 ( 2 0 0 7 ) 2 0 -3 0 ava i l a b l e a t w w w. s c i e n c e d i r e c t . c o m w w w. e l s ev i e r. c o m / l o c a t e / b r a i n r e s

Research paper thumbnail of Failure of estrogen to protect the substantia nigra pars compacta of female rats from lesion induced by 6-hydroxydopamine

Research paper thumbnail of Temporal profiles of the in vitro phosphorylation rate and immunocontent of glial fibrillary acidic protein (GFAP) after kainic acid-induced lesions in area CA1 of the rat hippocampus: demonstration of a novel phosphoprotein associated with gliosis

Brain Research, 1997

The in vitro phosphorylation rate and immunocontent of glial fibrillary acidic protein was studie... more The in vitro phosphorylation rate and immunocontent of glial fibrillary acidic protein was studied in slices of area CA1 of the rat hippocampus after stereotaxic injection of 1 nmol of kainic acid. For controls the contralateral hippocampus was injected with saline.

Research paper thumbnail of Gonadal hormone regulation of glial fibrillary acidic protein immunoreactivity in the medial amygdala subnuclei across the estrous cycle and in castrated and treated female rats

Brain Research, 2006

The medial amygdala (MeA) is a sexually dimorphic area that modulates neuroendocrine and behavior... more The medial amygdala (MeA) is a sexually dimorphic area that modulates neuroendocrine and behavioral activities and where gonadal hormones play an important role in neuronglial and synaptic plasticity. Immunohistochemistry was used to identify the astrocytic marker glial fibrillary acidic protein (GFAP) in the different MeA subnucleianterodorsal (MeAD), posterodorsal (MePD) and posteroventral (MePV)of intact female rats in the different phases of the estrous cycle and in ovariectomized females treated with hormonal substitutive therapy. Data semi-quantified by optical densitometry showed that, in the proestrus phase, the GFAP immunoreactivity (GFAP-ir) was higher when compared to the other phases of the estrous cycle (P < 0.02). GFAP-ir was also higher in the MePD than in the MeAD or in the MePV (P < 0. 02). In ovariectomized females, injections of estradiol alone or estradiol plus progesterone increased GFAP-ir in the MePD and in the MePV (P < 0.001), but not in the MeAD (P > 0.3), when compared to control data. These findings suggest that astrocytic GFAP in the MeA subnuclei can be affected either by physiological levels or by hormonal manipulation of the ovarian steroids, which may contribute to the plasticity of local and integrated functional activities of these brain areas in female rats.

Research paper thumbnail of Glial alterations in the hippocampus of rats submitted to ibotenic-induced lesion of the nucleus basalis magnocellularis

Behavioural Brain Research, 2008

Lesion of the nucleus basalis magnocellularis (nbm) is a suitable approach to study cognitive def... more Lesion of the nucleus basalis magnocellularis (nbm) is a suitable approach to study cognitive deficit and behavior alterations involving cholinergic dysfunction, which is associated with the major types of dementia. Cortical astrogliosis also has been described in this model, but it is not clear whether hippocampal astrocytes are activated. In this study, we investigated possible specific astrocyte alterations in the hippocampi of Wistar rats submitted to nbm damage with ibotenic acid, investigating the content and immunohistochemistry of glial fibrillary acidic protein (GFAP), as well as S100B protein content, glutamate uptake and glutamine synthetase activity on the 7th and 28th post-lesion days. Cognitive deficit was confirmed by the step-down inhibitory avoidance task. Interestingly, we found a decrease in GFAP content, S100B content and glutamate uptake activity in the hippocampus on the 28th day after nbm lesion. No alterations were observed in glutamine synthetase activity or in the cerebrospinal fluid S100B content. Although our data suggest caution in the use of nbm lesion with ibotenic acid as a dementia model, it is possible that these alterations could contribute to the cognitive deficit observed in these rats.

Research paper thumbnail of Prenatal Stress Produces Social Behavior Deficits and Alters the Number of Oxytocin and Vasopressin Neurons in Adult Rats

Neurochemical Research

The present study investigated the long-lasting effects of prenatal repeated restraint stress on ... more The present study investigated the long-lasting effects of prenatal repeated restraint stress on social behavior and anxiety, as well as its repercussions on oxytocin (OT) and vasopressin (VP)-positive neurons of the paraventricular (PVN) and supraoptic (SON) nuclei from stressed pups in adulthood. Female Wistar rats were exposed to restraint stress in the last 7 days of pregnancy. At birth, pups were cross-fostered and assigned to the following groups: prenatally non-stressed offspring raised by prenatally non-stressed mothers (NS:NS), prenatally non-stressed offspring raised by prenatally stressed mothers (S:NS), prenatally stressed offspring raised by prenatally non-stressed mothers (NS:S), prenatally stressed offspring raised by prenatally stressed mothers (S:S). As adults, male prenatally stressed offspring raised both by stressed mothers (S:S group) and non-stressed ones (NS:S group) showed impaired social memory and interaction. In addition, when both adverse conditions coexi...

Research paper thumbnail of Hippocampal alterations in rats submitted to streptozotocin-induced dementia model are prevented by aminoguanidine

Journal of Alzheimer's disease : JAD, 2009

Although the exact cause of Alzheimer's disease remains elusive, many possible risk factors a... more Although the exact cause of Alzheimer's disease remains elusive, many possible risk factors and pathological alterations have been used in the elaboration of in vitro and in vivo models of this disease in rodents, including intracerebral infusion of streptozotocin (STZ). Using this model, we evaluated spatial cognitive deficit and neurochemical hippocampal alterations, particularly astroglial protein markers such as glial fibrillary acidic protein (GFAP) and S100B, glutathione content, nitric oxide production, and cerebrospinal fluid (CSF) S100B. In addition, prevention of these alterations by aminoguanidine administration was evaluated. Results confirm a spatial cognitive deficit and nitrative stress in this dementia model as well as specific astroglial alterations, particularly S100B accumulation in the hippocampus and decreased CSF S100B. The hippocampal astroglial activation occurred independently of the significant alteration in GFAP content. Moreover, all these alterations...

Research paper thumbnail of Ultrastructural analysis of the dorsal body gland of the terrestrial snail Megalobulimus abbreviatus (Becquaert, 1948)

Brazilian journal of biology = Revista brasleira de biologia

The ultrastructure of the reproductive gland, dorsal body (DB), of Megalobulimus abbreviatus was ... more The ultrastructure of the reproductive gland, dorsal body (DB), of Megalobulimus abbreviatus was analysed. Electron microscope immunohistochemistry was used to detect FMRFamide-like peptides in the nerve endings within this gland. Nerve backfilling was used in an attempt to identify the neurons involved in this innervation. In M. abbreviatus, the DB has a uniform appearance throughout their supraesophageal and subesophageal portions. Dorsal body cells have several features in common with steroid-secreting gland cells, such as the presence of many lipid droplets, numerous mitochondria with tubular cristae and a developed smooth endoplasmic reticulum cisternae. Throughout the DB in M. abbreviatus numerous axonal endings were seen to be in contact with the DB cells exhibiting a synaptic-like structure. The axon terminals contained numerous electron-dense and scanty electron-lucid vesicles. In addition, the DB nerve endings exhibited FMRFamide immunoreactive vesicles. Injection of neura...

Research paper thumbnail of Acetylcholinesterase distribution in the central nervous system of the Megalobulimus oblongus (Gastropoda, Pulmonata)

Archives d'anatomie, d'histologie et d'embryologie normales et expérimentales

The acetylcholinesterase (AChE) in the central nervous system (CNS) of the Megalobulimus oblongus... more The acetylcholinesterase (AChE) in the central nervous system (CNS) of the Megalobulimus oblongus was demonstrated by using Koelle and Friedenwald's procedure. The AChE positive reaction was revealed in the nervous cell bodies and processes in the different ganglia of the CNS. The largest number of strong positive neuronal subsets reside in pedal and buccal ganglia. Other positive cell bodies are also located in clusters in the left portion of the visceral ganglion, meso and postcerebrum, and pleural ganglia. In some neurons the enzymatic reaction only appeared at trophospongium level. The neuropilian synaptic areas also exhibited AChE reactivity. These data provide further evidence that AChE is present in neuronal bodies of the CNS of this pulmonate snail, and in some areas is probably involved in cholinergic circuits.

Research paper thumbnail of Distribution of NADPH-diaphorase activity in the central nervous system of the young and adult land snail Megalobulimus abbreviatus

Tissue and Cell

Nitric oxide (NO) is a gas produced through the action of nitric oxide synthase that acts as a ne... more Nitric oxide (NO) is a gas produced through the action of nitric oxide synthase that acts as a neurotransmitter in the central nervous system (CNS) of adult gastropod mollusks. There are no known reports of the presence of NOS-containing neurons and glial cells in young and adult Megalobulimus abbreviatus. Therefore, NADPH-d histochemistry was employed to map the nitrergic distribution in the CNS of young and adult snails in an attempt to identify any transient enzymatic activity in the developing CNS. Reaction was observed in neurons and fibers in all CNS ganglia of both age groups, but in the pedal and cerebral ganglia, positive neurons were more intense than in other ganglia, forming clusters symmetrically located in both paired ganglia. However, neuronal NADPH-d activity in the mesocerebrum and pleural ganglia decreased from young to adult animals. In both age groups, positive glial cells were located beneath the ganglionic capsule, forming a network and surrounding the neuronal...

Research paper thumbnail of Carbohydrate metabolism in the central nervous system of the Megalobulimus oblongus snail during anoxia exposure and post-anoxia recovery

Journal of Experimental Zoology Part A Comparative Experimental Biology

The effects of anoxic exposure and the post-anoxia aerobic recovery period on carbohydrate metabo... more The effects of anoxic exposure and the post-anoxia aerobic recovery period on carbohydrate metabolism in the central nervous system (CNS) of the land snail Megalobulimus oblongus, an anoxia-tolerant land gastropod, were studied. The snails were exposed to anoxia for periods of 1.5, 3, 6, 12, 18, or 24 hr. In order to study the post-anoxia recovery phase, snails exposed to a 3-hr period of anoxia were returned to aerobic conditions for 1.5, 3, 6, or 15 hr. Glycogen and glucose concentrations in the CNS, hemolymph glucose concentration, and glycogen phosphorylase (active form, GPa) activity in the CNS were analyzed. Anoxia does not significantly affect the concentration of CNS glucose but induces hyperglycemia and a reduction of CNS GPa activity. The glycogen concentration was decreased at 12 hr of anoxia; however, by 18 and 24 hr in anoxia, the glycogen content was not significantly different from basal control values. During the post-anoxia period, the reduction in GPa activity and ...